Merle Henkenius, Popular Mechanics

Most vinyl siding is designed to meet the American Society of Testing and Materials Standard 3679 -- a minimum standard for vinyl siding -- so look for a certification label on each carton.

The Vinyl Siding Institute has created a new certification program, ASTM D-3679, which sets higher standards and verifies any advertised claims. To be certified, a siding must pass tests for weathering performance, wind-load resistance, impact resistance, surface distortion, heat shrinkage and linear expansion. This program is still fairly new and not every siding will measure up yet, but it's a step in the right direction.

Many manufacturers offer a Good-Better-Best product selection to reach all segments of the market. The cost of upgrading one level is usually not substantial -- as little as $30 to $40 per square. But, depending on the manufacturer and the materials involved, there is the potential for a significant price increase. Some installers offer only one level of product quality, preferring to work only with the best, while others start with a basic price and build up from there in clearly defined increments.

One measure of quality is the thickness of the vinyl. It can range between .035 and .050 in., with the better panels starting around .042 in. Builder's-grade panels are often lighter, starting around .040 in. Avoid anything thinner.

Thickness not only influences the stiffness of the siding, but also its thermal stability. Thin panels can bulge and buckle, and those thinner than .040 in. can sag in hot weather. Thickness is only one of the factors affecting stiffness, but it's a big factor when comparing competitively priced panels. The stiffer the panel, the better it will bridge irregularities in a wall, so a heavier panel is a good idea when going over uneven older siding. Rigid panels are also better at surviving high winds.

Beefing up the nailing hem, the slotted section of the panel that's nailed to the house, is another tactic that adds rigidity. Several manufacturers employ a rolled nailing hem that's double the thickness of the panel itself for extra stiffness (Photo 1). Wolverine Siding's StabilizeR system features a fiberglass rod running through a fold in the nailing hem (Photo 2). Even more innovative is Wolverine's NailTight Flexible hem design -- a panel hung from a nylon suspension ribbon. As its name implies, it can be nailed tight, even by using a roofing stapler. This speeds installation and yields a straight wall with improved wind resistance.

The siding's profile also influences stiffness. Siding can be made substantially stronger just by increasing the depth of the return in the profile from 1/2 to 3/4 in. The Dutch-lap profile, offered by many manufacturers, is one of the more noticeable efforts at stiffening through profile design (Photo 3).

Fancy Siding, Fancy Trim

Just because consumers seem to be getting used to vinyl's traditionally bland appearance doesn't mean manufacturers have stopped trying to rival the look of classic wood. In fact, that's where the really innovative advances are being made. It can be as simple as an extra line in a profile or as ambitious as attempting to copy the look of split-cedar shingles. One example is beaded siding (Photo 4) made by both Revere Building Products and Owens Corning. It's based on a traditional architectural detail of mid-Atlantic Coast homes.

Another recent development is variegated color in some premium sidings. Highlight colors are achieved in two ways -- either by dropping beads of pigment into the extruder as the siding is being made, or by applying nearly clear acrylic films over a weathered cedar-embossed panel. The result is a very natural appearance, unlike anything available before.

A more significant departure from standard lap siding is paneling with the look of weathered or painted cedar shakes. This can be used as an accent on gables or as a whole-house siding treatment (Photo 5).

And finally, many manufacturers now offer the look of hand-sawn, fish-scale cedar shingles (Photo 6). These come in 36- to 64-in. panels that look convincingly Old World, whether used on a true Victorian home or its modern suburban counterpart. As for costs, assuming standard vinyl siding has a contractor's price of $65 per square, cedar-shake siding would run about $160 per square and fish-scale shakes about $240 per square, uninstalled. It's pricey, but worth it if you're after a striking new look.

But it's the new trim options that really improve the look of the average vinyl siding installation, and most of them are not terribly expensive. For example, instead of the typical flat, boring corner details of conventional vinyl, makers now offer extra-wide corner boards in both smooth and fluted profiles. The two sides are joined by classic quarter-round trim, which is available in matching or contrasting colors (Photo 7). You can even add a touch of class to the underside of roof overhangs with beaded soffit panels.

When it comes to window detailing, the traditional look of wood without the fuss has never been easier to find. Makers offer a range of alternatives from Victorian-style corner rosettes accenting 3 1/2-in.-wide channel trim to classic crown molding (Photo 8). And many of these trimpieces are available in light and dark designer colors.

Finally, you can have a decorative sunburst gable, in solid or alternating colors. Decorative sunbursts are expensive, however. Each piece must be custom cut and pop-riveted to the adjoining piece, so it's an all-day job costing around $1,000 (Photo 9).